The P1135 is a low current malfunction on the AFR heater circuit of bank 1 sensor 1. Ideally you need to test the voltage at the computer Pin HAF1 it should read 12 volts. With in a minute or two the voltage should drop to 0 to 2 volts when the computer turns the ground circuit on to energize the circuit and heat up the sensor. If the voltage is not 12 volts then you need to check the voltage at the sensor. If the computer never drops the voltage then the driver is bad in the computer. 90% of the time the AFR sensor is bad but in some rare cases I have seen them take out the computer also. Click the link below for some more info. The P1133 is low response of the same sensor and the P0125 means the sensor is not responding in time in correlation to coolant temp. B1S1 sensor is in the manifold back by the firewall no the radiator. If the sensor starts to stick put brake fluid on the threads then let it set and then work it back and forth and it will come out. Do not buy cheap after market sensors this is an AFR sensor not an O2 sensor. They are different. Go to www.metrotoyotapartsnow.com for online wholesale prices.
Is there only one AFR sensor? Will I be able to find tha part by that name?
There are two AFR sensors B1 which is usually referred to as the right sensor. Then there is B2 which is right at the radiator in the manifold and may be considered the left sensor. If you go to that website and enter in AFR sensor it will bring them up. They may even be the same sensor part number on this vehicle. The other option is if you shoot them an e-mail with your vehicle identification number they can give you an exact part number and price.